So, do all top level links need a URL?
I'm sure they never used to...
As is often the way with these glitches, the range right problem for onClick menus seems to have resolved itself. Very frustrating, especially as I'm not doing anything differently to before the upgrade, when it all worked perfectly anyway.
The intermittent problem with the Organiser drop down menus not actually going anywhere onClick also seems to be sorted now.
Thanks